Getting Started with Kapsel – Part 3 — AppUpdate (SP13+)

AppUpdate

The AppUpdate plugin is used to enable the contents in the www folder (HTML, JavaScript, CSS, images, etc.) of a deployed Kapsel app and its config.xml to be updated. As an example, a new project named AppUpdateDemo will be created and used to demonstrate how to update a deployed app. A Kapsel app with the AppUpdate plugin installed will check with the SMP 3.0 server on startup to see if there is a newer revision of the app available. The revision number of the Kapsel app is automatically incremented with each deployment to the SMP 3.0 server. If the revision on the server is higher than the revision in the config.xml on the device or simulator, then a notification is shown asking the user if they wish to accept the update.
For additional details see C:\SAP\MobileSDK3\KapselSDK\docs\api\sap.AppUpdate.html or Using the AppUpdate Plugin.

The following steps will demonstrate this plugin.

Add the AppUpdate plugin and optionally the logger plugin if you wish to view the messages logged by the AppUpdate plugin. The log level is set to debug if sap.Logger is detected on line 12 of index.html.

Due to a long delay on Android while assets are being copied during the first app update, it is recommended to either not specify hybridapprevision or use value=”0″. When hybridapprevision is not present or set to 0, during the first client update, the client will request the server to send the complete contents of the www folder rather than just the files that changed between the revision that is reported on the client and the revision on the server.

Prepare, build and deploy the app with the following command.

cordova run android
or
cordova run ios

In the All Output tab in Xcode or in the Android Device Monitor (monitor.bat), under the LogCat view, the debug output from the AppUpdate plugin can be seen. Note that the LogCat view provides a feature to filter messages. The filter shown below is based on the tag SMP_APP_UPDATE.
Notice above that when the app starts, the AppUpdate plugin checks with the SMP server to see if there is a newer revision of the app. The current revision of the app is appRevision 0. There is not a newer deployed version of the app on the server so a message No update available is logged.

The Kapsel command line interface (CLI) provides a way to generate a zip file that contains the HTML files that make up the app. This zip file can then either be uploaded to the SMP 3.0 server using the Management Cockpit or it can be uploaded using the Kapsel command line interface. Open a command prompt or shell to the folder

C:\SAP\MobileSDK3\KapselSDK\cli
~/SAP/MobileSDK3/KapselSDK/cli

Run

npm install -g

On a Mac it may be necessary to run

sudo npm -g install

Change directories to the directory containing the project and run the below commands to generate a zip file containing the HTML files that make up the application and then upload the zip file to the SMP 3.0 server.

Note, if the deploy command fails with the following error {“errorCode”:”KAPSEL_APP_ARCHIVE_APPLICATION_CONTENT_VALIDATION_FAIL”}, this may be due to a check that the SMP server makes on icon elements. It attempts to validate the config.xml and notices that the referenced icon does not exist in the zip file. Icons cannot be updated by the appupdate plugin so as a workaround comment out the icon resources from the config.xml or update the default ones rather than specifing them in the config.xml.

Note, if the deploy command fails with the following error, try adjusting the no_proxy environment variable to exclude the host being deployed to.

The package command can optionally take a platform such as android or iOS. The parameters to the deploy command are the app ID, the SMP 3.0 server host name, the user id, and password for the SMP 3.0 server. After running this command the Management Cockpit will show that revision 1 has been uploaded to the server.

Close and reopen the app. This time when the AppUpdate plugin will see that revision 1 is available.

Notice above that the response also indicates where to download the app from. If you are using a reverse proxy server between the devices and the SMP server, you may need to include a rule for the reverse proxy to rewrite this address. See also Apache Module mod_substitute. In the below example the apache reverse proxy server is at smpqa12-03.sybase.com and the SMP server is installed on smpqa-win12-03.sybase.com:8080.

The www folder on the Android device or simulator is read only and cannot be updated directly, so the first app update causes the entire contents of the www folder to be copied to a new location causing the size of the deployed application to increase. Updates after the first update should be proportional to the size of the new files being added.

At this point the version of the application on the device is the same as the version on the server.

Update C:\Kapsel_Projects\KapselGSDemo\www\index.html and change the body’s background-color to some other color such as silver.

<style type="text/css">
body {
background-color: silver;
}
</style>

Copy the contents of the www folder to the platform specific www folder of the project using prepare.

Close and reopen the app and notice that the staged version of the app is downloaded.

Testing Changes before Deploying

Note, it is important to test the changes before publishing them to the server. If an error is introduced, it could cause the application to break and potentially prevent future updates from being downloaded. You can also validate your JavaScript with tools like JSLint, or JSHint. CSS can be validated with CSS Lint. If you encounter a problem after an update has occurred and you are using an iOS simulator, the contents of the update can be viewed at the following location.

Note, the above location can be seen as the first line in the Xcode All Output window.

If using an Android emulator, the updated files can be viewed at the following location.

data\data\com.kapsel.gs\files\download\www

One technique to aid with this problem is to open an error page that can check for new updates if an error is detected.
Replace the contents of C:\Kapsel_Projects\KapselGSDemo\www\index.html with following contents.

Line 12 can be uncommented which makes a call to a non-existent JavaScript method. The app that now has an error in it can be packaged and deployed to the SMP 3.0 server. When the app is reopened, the newer version is uploaded and the error handler detects an error and redirects to the error page.